Luminescence and excitation energy transfer in new fluoride crystals containing rare earth ions

Spectroscopic characteristics of Pr3+ and Eu3+ in K2Na2GdF7, K5Li2GdF10 and K3GdF6 fluoride matrices are considered. Crystal structures of these compounds have been ascertained based on X-ray measurement on single crystal samples. Energies of lattice vibrations have been derived from IR and Raman spectra. Spectroscopic features of crystals in the VUV region were studied using experimental facilities of the Superlumi station at HASYLAB in Hamburg. High-resolution spectra and decay curves of luminescence in the visible were used to determine the energy levels and excited state relaxation dynamics of luminescent ions. Relevance of energy transfer processes, which feed the DJ5 levels of Eu3+ and the P03 level of Pr3+, is discussed.